Continuous molding machine



June 24, 1941- w WEB$TER 2,246,907

CONTINUOUS MOLDING MACHINE Filed April 12, 1940 2 Sheets-Sheet 1H-JVENTOR ATTORNEYS.

June 24, 1941. w, R, WEBSTER CONTINUOUS MOLDING MACHINE Filed April 12,1940 2 Sheets-Sheet 2 E N R O T A Patented June 24, 1941 UNITED STATESPATENT OFFICE 2,246,907 CONTINUOUS MOLDING MACHINE William R. Webster,Bridgeport, Conn. Application April 12, 1940, Serial No. 329,247

7 Claims.

This invention relates to continuous moldin machines and more especiallyto machines for molding bars or rods of non-ferrous metal.

Heretofore, continuous molding machines have not been satisfactory dueto the lack of uniformity in the molded rods or bars. The lack ofuniformity has been due to the absence of means 'for controlling therelation of the teed rate of the molten metal to the discharge rate ofthe molded bar or rod. If the molded rod or bar is discharged at too lowa rate, the molten metal overflows the mold and if the discharge rate istoo great, then liquid metal is discharged instead of solidified metal.

An object of this invention is to provide a continuous molding machinein which the relation between the feed rate of molten metal and thedischarge rate of the molded bar or rod is so controlled that uniformityis obtained.

A machine embodying this invention preferably comprises a moldingchamber having an inlet and an outlet with the outlet desirably at alower elevation than the inlet. The chamber may be a stationarycontinuous cylinder or may be composed of a movable endless memberhaving a peripheral channel in combination with a cover for the channelover a portion of its length, and the cover may be an endless band orthe like movable in synchronism with said member. Means are provided tointroduce molten metal into the chamber inlet and means are provided topromote solidification of the metal in its passage through the moldingchamber. Automatic means are provided for regulating the ratio of moltenmetal inflow to the linear emergent speed of the solidified metal andsuch means preferably is of a nature to be responsive to the level ofmolten metal in the chamber, although such means alternatively may beresponsive to the temperature of the emerging solidified metal. Theregulation of the ratio of molten metal inflow to solidified metaloutput is so controlled that back-up of the metal in the channel withconsequent overflow is prevented as well as the possibility of metalemerging from the molding channel in fluid form.

Other objects, novel features and advantages of this invention willbecome apparent from the following specification and accompanyingdrawings, wherein:

Fig. 1 is a sectional view partially in elevation of an apparatusembodying the invention, certain of the parts being shown schematically;

Fig. 2 is an elevation of a modification of the embodiment illustratedin Fig. 1;

Fig. 3 is an elevation partly in section of a difierent embodiment ofthe invention;

Fig. 4 is a sectional view of a modification of the embodiment shown inFig. 3;

Fig. 5 is an enlarged fragmentary view of the modification illustratedin Fig. 3, and

Fig. 6 is a section on the line 6--.-5 of Fig. 5.

In Figs. 1 and 2, I0 is a molding tube or chamber of tubular form openat both ends and housed within a casing I I to provide a jacket forcirculating cooling liquid around the moldin tube. Pipes l2 and 13 areprovided for supplying and withdrawing the cooling liquid. A pouring boxI4 is supported above the molding tube II by struts i5 and a pipe [6extends from the bottom of the pouring box it into the mold tube III apredetermined distance below the top of the molding tube. Molten metalto be cast is delivered from the furnace to suitable means, such as atiltable ladle I'I from which the molten metal is discharged into thepouring box H, the rate of flow from the pouring box through the pipe l6into the molding chamber being constant.

Means well known in the art, but not disclosed herein are provided forinitiating the forming of the ingot blank or stool l8 in the mold, anexample of such means being illustrated in the patent to Williams, No.2,079,644. The ingot I8 is withdrawn from the mold tube by any suitableextracting or withdrawing mechanism, such for example, as toothedrollers l9 which engage the surface of the ingot. These rollers areoperated in synchronism by a driving screw 20 provided at one end with agear 2i which meshes with a pinion 22 mounted on the armature shaft 01 amotor 23. The motor 23 is connected in circuit with a variable currentsupply 24, the operation of which is controlled by a photo-electric cell25. A quartz rod 26 or the like is arranged with one end properlypositioned to deliver light to the photo-electric cell 25 and extendsinto the molding tube III, the arrangement being such that the axis lineof the rod is angularly related to the surface of the molten metal inthemolding tube. With this arrangement, light is transmitted from themolten metal through the rod 2 to the photo-electric cell when theheight of molten metal in the tube lies above the point at which theaxis line intersects the tube wall, but is transmitted only slightly ornot at all when the molten metal level is below such point.

The inter-connection between the photo-electric cell 25 and the variablecurrent supply 24 is such that a decrease in the light transmitted tothe photo-electric cell results in a decrease in the current supplied tothe motor 23 with consequent decrease in the speed of rotation of thetoothed wheels I9 and retardation of the emergent speed of the ingot I8and that an increase in the light transmitted to the photo-electriccell-results in an increase in the current supplied to the motor 23 withconsequent faster rotation of the toothed wheels I! and acceleration ofthe emergent speed of the ingot. The emergent speed of the ingot is thusvaried in response to the height of the molten metal in the tube Ill andsince the supply of molten metal to the tube is at a constant rate,uniformity is maintained in the condition of the bar emerging from themolding chamber.

The apparatus may also be provided with alternate control apparatuscomprising a radiation pyrometer 21 or other suitable heat sensitivedevice arranged to be influenced by the temperature of the ingot as itleaves the molding tube. Such pyrometer is electrically connected to thevariable current supply 24 in such manner that an increase oftemperature in the emergent ingot results in a decrease in the currentsupplied to the motor 23 with consequent decrease in the emergent speedof the ingot while a decrease in the temperature of the emerging barresults in an increase in the current supplied to the motor 23 withconsequent increase in emergent speed of the ingot. The pyrometer 21 maybe used as a substitute for or in addition to the photo-electric cell 25and may not enter into the control of the motor 23 under normaloperating conditions.

In the modification illustrated in Fig. 2, an adjustable furnace 28 ofthe standard induction type is supported by the shaft 29 which carriesthe worm wheel 30. The nozzle 3| of the furnace is arranged to dischargeinto the pouring box l4. A worm wheel 32 meshes with the gear 30 and isdriven by variable speed means indicated generally at 33 and regulatedby the photoelectric cell 25. The variable speed means 33 is designed tocause rotation of the worm wheel 32 at a faster or slower peed,depending upon the height of the molten metal in the molding tube l0. Asthe height of the molten metal in the tube decreases, the rotationalspeed of the worm 32 is increased to tilt the furnace 28 to increase therate of flow of the molten metal into the tube and this causes a rise inthe level of the molten metal in the tube. In the event of an increasein the height of molten metal in the tube H), the speed rate of the worm32 is decreased with a consequent reduction in the rate of flow ofmolten metal into the tube. Also, in thi embodiment, a radiationpyrometer 21 may also be used to regulate tilting of the furnace 28.Constant current is supplied to the motor 23 with resulting constantrotational speed of the toothed wheels I 9.

In the embodiment illustrated in Figs. 3 and 4, a molding wheel 40 iscarried by the shaft 4| and is provided with a peripheral channel 42.Over a portion of its length, the channel 42 is closed by an endlessband 45 which passes around guide rollers-46 and 41 and a tensioningidler 48. The roller 46 is fixed to a shaft 49 and on the shafts 4| and49 are provided gears 50 and for effecting synchronism of the wheel 40and the band 45. The band 45 preferably is reinforced by a link chain 52of the Morse silent type, the chain being interposed between the bandand each of the rollers 46 and 41 and provided with suitable teeth toco-operate with the chain links, the

chain also passing around a tensioning roller 53. A pouring box 54 issupported adjacent the upper point of contact of the band with the wheeland has a nozzle portion extending into the covered portion of thechannel. A stripper 55 is provided for stripping the finished bar fromthe wheel. In Fig. 3, the shaft 49 is connected through suitable drivingmechanism with a variable speed power transmitter 56, which iscontrolled by a suitable balancing device 51 such, for example, as onecommonly known in the industry as a Micromax electric control which is asensitive balance for regulating the output in proportion .to demand andusually comprises an electrical controller unit and a relay detectorunit, which in the drawings are illustrated diagrammatically.

In the wall of the pouring box 54 is provided a quartz rod 26 with itslower end having the same arrangement a described in connection with thepreceding modifications (see Figs. 5 and 6). A photo-electric cell 25 isarranged to receive light from the end of the quartz rod 26 and issuitably connected to the transmitter 51. The inter-connection betweenthe photo-electric cell and the transmitter is such that an increase ofheight of the molten metal in the molding chamber results in an increaseof the rotational speed of the wheel 40 and a decrease in the height ofmolten metal in the molding chamber results in a decrease in the speedof the wheel.

In the modification of Fig. 4, an adjustable furnace 58 of the standardinduction type is supported by the shaft 5:; which carries the wormwheel 50. The nozzle 6| of the furnace is arranged to discharge into thepouring box 54. A worm wheel 62 meshes with the gear 50 and is driven byvariable speed means indicated generally at 53 and regulated by thephoto-electric cell 25. The variable speed means 63 is designed to causerotation of the worm wheel 62 at a faster or slower speed, dependingupon the temperature of the ingot l8 emerging from the channel in themolding wheel. As the height of the molten metal in the molding channeldecreases, the rotational speed of the worm 62 is increased to tilt thefurnace 58 to increase the rate of flow of the molten metal into thecovered portion of the wheel and in the event of an increase in theheight of the molten metal, the speed rate of the worm 62 is decreasedwith consequent reduction in the rate of flow of molten metal into themolding chamber. The wheel 40 is rotated at constant speed through themedium of a pinion 64 in mesh with the gear 5|.

In the embodiment illustrated in Figs. 3 and 4, means are provided topromote solidification of the metal in the covered portion of thechannel.

Such means are indicated generally by the reference character 65 andpreferably are of the same construction as illustrated in applicantscopending application, Serial No. 221,925. The unit 65 is'provided witha water supply pipe 66 and two outlets 61, 'all as fully shown anddescribed in said co-pending application.

In the embodiment illustrated in Figs. 1 and 2, the molding tube In maybe of any desired crosssection, although in the drawings, it is shown ascylindrical. The cross section of the tube l0 alone would dependentirely upon the shape of the ingot which it is desired to produce.Likewise, in the embodiment illustrated in Figs. 3 and 4, the channel 42may be of any desired cross section. Furthermore, it is to be understoodthat various modifications may be made in the structure above described,without in any way departing from the spirit of the invention as definedin the appended claims.

This application is a continuation in part of William R. Websterapplication, Serial No. 221,925, filed July 29, 1938.

I claim:

1. A continuous molding apparatus comprising a molding chamber having aninlet and an outlet, means for continuously introducing molten metalthrough said inlet into said chamber, means to promote solidification ofthe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet, and means responsive to heightincrease of molten metal in said chamber to decrease the ratio of themolten metal fiow rate to the linear emergent speed of the solidifiedmetal discharged from said chamber and responsive to height decrease ofmolten metal in said chamber to increase the ratio of the molten metalfiow rate to the linear emergent speed of the solidified metal, saidlast-named means consisting of a light transmitting member extendinginto the upper end of said chamber in position to transmit light fromsaidmolten metal only when the level thereof exceeds a predeterminedheight and light sensitive means to which light is transmitted throughsaid member.

2. A continuous molding apparatus comprising a molding chamber having aninlet and an outlet. means for continuously introducing molten metalthrough said inlet into said chamber, means to promote solidification ofthe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet, and means responsive to heightincrease of molten metal in said chamber to increase the linear emergentspeed of solidified metal from said chamber and responsive to heightdecrease of the molten metal in said chamber to decrease the linearemergent speed of the solidified metal.

3. A continuous molding apparatus comprising a molding chamber having aninlet and an outlet, means for continuously introducing molten metalthrough said inlet into said chamber, means to promote solidification oithe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet, and means responsive to heightincrease of the molten metal in said chamber to decrease the fiow rateof molten metal into said chamber and responsive to height decrease ofmolten metal in said chamber to increase the fiow rate of molten metalinto said chamber, said lastnamed means consisting of a lighttransmitting member extending into the upper end oi. said chamber inposition to transmit light from said molten metal only when the levelthereof exceeds a predetermined height and light sensitive means towhich light is transmitted through said member.

4. A continuous molding apparatus according to claim 2 in which theheight responsive means comprises a light transmitting member extendinginto the upper end of said chamber in position to transmit light fromsaid molten metal only when the level thereof exceeds a predeterminedheight, and light responsive means to which light is transmitted throughsaid member.

5. A continuous molding apparatus comprising a molding chamber having aninlet and an outlet, means for continuously introducing molten metalthrough said inlet into said chamber, means to promote solidification ofthe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet. and temperature sensitive meansresponsive to temperature increase of the solidified metal emerging fromsaid chamber to increase the ratio of the molten metal fiow rate to thelinear emergent speed of solidified metal from said chamber andresponsive to temperature decrease of said solidified metal to decreasethe ratio of the molten metal flow rate to the linear emergent speed ofsaid solidified metal.

6. A continuous molding apparatus comprising a molding chamber having aninlet and an outlet, means for continuouslyintroducing molten metalthrough said inlet into said chamber, means to promote solidification ofthe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet, and temperature sensitive meansresponsive to temperature increase oi. the solidified metal emergingfrom said chamber to decrease the linear emergent speed of thesolidified metal and responsive to temperature decrease of saidsolidified metal to increase the linear emergent speed of solidifiedmetal.

"I. A continuous molding apparatus comprising a molding chamber havingan inlet and an outlet, means for continuously introducing molten metalthrough said inlet into said chamber. means to promote solidification ofthe molten metal in said chamber, means for withdrawing solidified metalfrom said chamber through said outlet, and temperature sensitive meansresponsive to temperature increase of the solidified metal emerging fromsaid chamber to increase the molten metal fiow rate and responsive totemperature decrease 01' said solidified metal to decrease the moltenmetal fiow rate.

WIILIAMR. WEBSTER.

